The present invention relates to refrigerant filtering and, more specifically, relates to a specialized method and apparatus for retaining and reconditioning fluorocarbon refrigerants.
The refrigeration industry has grown tremendously since the development of modern manufacturing techniques and the electrification of the country. In fact, refrigeration is presently the ninth largest industry in the United States. Almost every office building and manufacturing facility constructed within the last twenty years is at least partially air conditioned, and many homes are air conditioned as well. At some time during the life of the electro-mechanical refrigeration system, one or more of the units making up the system malfunctions and repair or replacement will be required. This typically involves disassembly of the sealed-gas system and replacing the fluorinated hydrocarbons (fluorocarbons) that are used as the refrigerant.
In industrial air-conditioning and refrigeration installations the units are quite large and employ relatively large horsepower electric motors to operate the compressors and blowers. In some systems the motor is integrally formed with the compressor and is arranged inside the compressor case. In any event, all electric motors are subject to burnout. Whether caused by a malfunction or just old age, the windings of the motor overheat and reach a temperature at which the insulation is destroyed and the windings become shorted out. While this situation is undesirable from the standpoint of replacing the motor, it is even more troublesome from the refrigeration system standpoint. This is so because typically when the motor burns out the compressor also reaches a very high temperature and, in the case where the refrigerant actually passes over the motor windings, the refrigerant will be substantially contaminated by carbon particles and other undesirable particulate hydrocarbons which are formed at this high temperature. It is then necessary not only to repair/replace the burned-out motor and compressor system but also to replace the fluorocarbon refrigerant. The common practice in the industry today is simply to vent the sealed system to the atmosphere and to permit the refrigerant, such as Freon, to escape into the atmosphere. This practice adds to the cost of the repairs, since this refrigerant is not inexpensive. Then it is often the customary practice to clean the system with a liquid refrigerant solvent, e.g., R-11 or Freon 11. It is understood that at normal ambient temperatures and under standard atmospheric pressures the liquid refrigerant will boil and is driven off as a gas. This practice of venting the refrigerant to the atmosphere has proven to be convenient and, once the repairs have been completed, the system is recharged using fresh refrigerant.
While permitting the refrigerant to escape into the atmosphere does present some cost disadvantages, there is apparently an even greater disadvantage. Recent scientific theories (based on laboratory modeling) have been advanced that the presence of flourinated hydrocarbons depletes the ozone layer surrounding and protecting Earth. This concern has been reflected in a recent federal ban on fluorocarbons for use as an aerosol propellant. Also, legislation has been proposed to limit the production of fluorocarbons to a level equal to 30% of the 1979 level of production. Accordingly, it is desirable if at all possible to prevent excessive escape of fluorocarbons into the atmosphere and also to conserve the supply of manufactured fluorocarbons.